Three-dimensional (3-D) visual effects have been around since the 1950s. Conventionally, 3-D visual effects have been realized in part by having the viewers wear glasses having a pair of polarized lens, a pair of chromatically opposite lens, or shutter glass spectacles. More recently, lens-free 3-D visual effects have been realized by using multiple cameras to capture multiple angles of a scene, wherein a monitor, employing a lenticular lens array, reconstructs the multiple views for display to the viewers. Such an arrangement is generally expensive and heavy. Another technique for producing lens-free 3-D visual effects is employing a parallax barrier that can reconstruct multiple views of a 3-D scene for display to viewers. The parallax barrier is relatively lower in cost and lighter in weight, as compared a monitor employing a lenticular lens array.
A 3-D autostereoscopic display based on parallax barrier can realize 3-D visual effects in part by having different pixels carrying different views of a 3-D scene. The 3-D autostereoscopic display is a technology that can combine multiple perspectives (e.g., multiple 2-D perspectives) of a 3-D scene into a single, integrated 2-D image. Using an autostereoscopic monitor, the single, integrated 2-D image can be displayed to a viewer such that each recorded view (e.g., 2-D image from each perspective) of the 3-D scene can be displayed to the viewer along its corresponding orientation. For instance, as the viewer moves from left to right (or right to left) in relation to the 3-D scene, the viewer can observe different views of the 3-D scene as if the viewer is looking at the actual 3-D environment depicted by the 3-D scene. In addition to displaying multi-view images to the viewer, the autostereoscopic techniques also can provide a 3-D sensation to the viewer as each of the viewer's eyes can perceive a slightly different image (e.g., different 2-D image from a different perspective) of the 3-D scene.
This 3-D technology has motivated numerous research works with the ultimate objective of developing different kinds of 3-D commercial products, such as television, photo frame, computer monitors, and toys, with 3-D technology. The concept also can be applied to display larger 3-D images via rear projection. This can be achieved by projecting the integrated images (e.g., integrated 2-D images that can form 3-D images) onto a projector screen which can be overlaid with a parallax barrier or a lenticular lens array.
However, when an ordinary 2-D image is displayed in this manner, the resolution can be significantly degraded (e.g., blurry) due in part to the ordinary 2-D image being negatively affected by the parallax barrier. In practice, it can be difficult to change the projector screen (e.g., rear projector screen) according to whether the displayed images are 2-D or 3-D in nature.
The degradation when displaying a projected ordinary 2-D image can be overcome with the use of an active parallax barrier in place of the passive parallax barrier. When ordinary 2-D content is displayed, the active parallax barrier can be totally, or substantially, transparent and have no effect on the projector screen, and, as a result, the ordinary 2-D content can be displayed without being degraded by the active parallax barrier. When 3-D content is displayed, the pattern on the active parallax barrier can be activated to become partially opaque, and different views of the 3-D images can be directed to their corresponding directions, based at least in part on the pattern.
However, conventionally the pattern on the active parallax barrier is activated manually, which can be cumbersome and inefficient. Further, enabling switching of an active parallax barrier to enable desired display of 3-D content and ordinary 2-D content can require modification of the original hardware circuit and/or software of the projector (or a device which drives the projector). It also may be necessary to provide a power supply to the active parallax barrier, and establish some kind of communication link (e.g., RF, infrared, etc.) between the active parallax barrier and the projection system.
Today, there is no way of efficiently controlling the display of 3-D content and ordinary 2-D content via the same display without the ordinary 2-D content appearing to be degraded, without a user having to manually switch the active parallax barrier on and off and/or without modification of the projection system (e.g., rear projection video projector). Further, conventional techniques for providing power to the active parallax barrier can be inefficient for a variety of other reasons. The above-described deficiencies of today's systems are merely intended to provide an overview of some of the problems of conventional systems, and are not intended to be exhaustive. Other problems with the state of the art and corresponding benefits of some of the various non-limiting embodiments may become further apparent upon review of the following detailed description.